Smart campus relies on IoT technology to realize teaching management, location monitoring, business processing and other teaching and management activities, this paper draws on the characteristics of the development of smart campus, and builds a decision support system for educational management of smart campus by applying the conditions of IoT technology. The IoT multi-sensor is used to collect educational management data, and the Grobes criterion is applied to exclude the data with too large an error, and the consistency test is performed on the collected data. The least squares method and variance calculation are combined to process the multi-sensor data to optimize the data fusion accuracy. Comparison tests were conducted to analyze the fusion accuracy and variance of the observed data under different methods. Distribute questionnaires online and offline to analyze the feasibility of the construction of IoT in smart campus. Collate the ratings of teachers and students on the educational management decision support system of the smart campus, in which the ratings of teachers and students on the educational management decision part of the school are concentrated in the range of 0.7 to 0.8, and the overall rating of the educational management decision support system of the smart campus is 86.453 points.